Arpeggio keyboard

ABSTRACT

An arpeggio keyboard assembly for an electronic organ characterized by extreme simplicity and a major reduction of parts.

United States Patent 1191 Dyle et al. Oct. 14, 1975 [54] ARPEGGIOKEYBOARD 3,180,197 4/1965 Von Gunten 84 425 x 3,198,055 8 1965 v G 1 84425 x [75] Inventors Charles Dyle chlcagm 3,305,620 2/1967 8 4/l.l7Edwards, Lake Zurlch, both 3,308,253 3 1967 Krakinowski... 200 159 13 x3,591,749 7 1971 Comstock 200/159 B x [73 Asslgnee' g Corporatmn Chlcago3,600,528 8/1971 L/eposavic 200 5 A 3,624,583 11 1971 Nakada 84/DlG. 722 i 17 1974 3,668,337 6/1972 Sinclair 200/5 A 3,668,698 6/1972Demirdjioghlou et al. ZOO/DIG. l [21] Appl. No.: 461,662 3,699,29410/1972 Suddeth 200/159 B x 3,715,443 2 1973 Ishimura 84 1.01 RelatedData 3,732,389 5/1973 Kaelin et al. 200 1 R x Continuation of 81, uly 7,97 3,743,797 7 1973 Hoffman 200/1 R abandoned. 3,757,024 9 1973 Stinson,Jr. et al 84/l.l7

[52] US. Cl. 84/423; 84/425; 84/DIG. 7; Primwy Examiner joseph Hanan,

2200/1 R; ZOO/5 A; ZOO/250; 340/365 A Assistant ExaminerStanley J.Witkowski [51] Int. Attorney g or n Bergstedt [58] Field of Search84/1.01, 1.17, 439, 440, 84/DIG. 7, D16. 22, 423, 425, 427, 433; 200/1R, 1 A, 5 R, 5 A, 159 R, 159 B, 250, 1 ABSTRACT 1316- 1; 340/365 R 365 AAn arpeggio keyboard assembly for an electronic organ characterized byextreme simplicity and a major [56] References c'ted reduction of parts.

UNITED STATES PATENTS 12/1964 Von Gunten 84/425 X 2 Claims, 7 DrawingFigures US. Patent Oct. 14, 1975 ARPEGGIO KEYBOARD This is acontinuation, of application Ser. No. 272,681 filed July 17, 1972, andnow abandoned.

BACKGROUND OF THE INVENTION In US. Pat. No. 3,358,070 to Alan C. Youngdated Dec. 12, 1967, and US. Pat. No. 3,358,091 to Charles Dyle datedDec. 12, 1967, there is shown an arpeggio device upon which the presentinvention is intended to improve. A keyboard is formed of uniform,aligned, small rounded keys spanning all notes of three octaves, suchthat a thumb or finger may be run over the keyboard smoothly, and allthe keys will be consecutively depressed and released. Each set ofoctavely related keys is connected to a separate bus which is connectedin series to the like octavely related notes of the principal lowerkeyboard of the instrument and each key is connected individually to akeyer for the tone generators. Thus, as a note or chord is sounded onthe principal lower keyboard and a finger is run along the arpeggiokeyboard, only those notes the same or-octavely related to the notesplayed on the principal keyboard will be sounded, securing perfectconsonance of the arpeggio with the note or chord.

The arpeggio keyboard described in the above patents incorporates asseparateelements individual keys, switch contacts, biasing springs,etc., for each individual note of the arpeggio, amounting, in all, toabout 300 parts with the attendant complexity of assembly.

SUMMARY OF THE INVENTION The simplified arpeggio keyboard of the presentinvention effects a vast reduction in the number of basic parts tosimplify assembly greatly and reduce the cost substantially.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a printedcircuit board with terminal pins attached;

FIG. 2 is a plan view of the spacer;

FIG. 3 is a plan view of the contact strip;

FIG. 4 is a plan view of the pressure pad; and

FIG. 5 is a plan view of the cover strip, all of which, sandwichedtogether, form the keyboard of the present invention;

FIG. 6 is a transverse section through the assembled keyboard takenalong the line 66 of FIGS. l-5; and

FIG. 7 is a perspective view of the keyboard mounted in the front stripof an electronic organ, the front strip being in the front strip of anelectronic organ, the front strip being broken away in part to show themethod of mounting.

DESCRIPTION OF THE PREFERRED EMBODIMENT In a preferred embodiment thekeyboard 10 consists of five laminations; a printed circuit board 12, aspacer 14, a contact strip 16, a pressure pad 18, and a cover 20.

The circuit board 12 consists of an epoxy-glass substrate 22 with bothsides thereof having circuit elements printed thereon; an outer, switchside 24 and an inner, bus side 26. The circuits of both sides are shownin Fig. 1, their interrelation being best understood from sucnsuperposed presentation. The circuitry on the switch side 24 is shown inrelatively thick, scaled lines and the circuitry on the bus side 26 inthin lines, not

necessarily to scale. It will be appreciated that the actual busses maybe of any suitable width. The switch side has printed 49 switches 28thereon, thus providing four chromatic octaves and a top C, consistingof spaced pairs of conductive strips extending transversely across theboard 12. As illustrated, the left strip 30 of each of these switchesincludes a bus connection 32 and the right strip 34 extends to a notepin receptacle 36 adjacent the lower edge 38 of the board.

The reverse or bus side 26 has 12 parallel busses 40 printed thereon,one for each of the tones of the chromatic scale, extendinglongitudinally of the board in space relation and sloping at the righthand end toward the lower edge 38 of the board where they terminate inbus pin receptacles 42.

The note pin receptacles 36 and bus pin receptacles 42 are perforationsarranged in a line along the lower edge 38 of the board 12 surrounded byconductive material, the plating of the bus pin receptacles extendingfrom the bus side through the perforations to the outer or switch side24 of the board for convenience of pin connection as will be laterdescribed.

In the configuration illustrated, the uppermost bus is assigned to thenote C, the lowermost to C the next above to D, and so on up to the Cbus. The left-most switch is assigned to the note C, and from that C,the switches are successively assigned to the next adjacent semitonethrough four octaves of the chromatic scale to C. At each point ofcrossing of the left hand elements 30 of the C, C, C, C', C"" switchesand the C bus, the board is perforated as at 32 with the platingextended through the perforations to connect those switch elements tothe C bus. Similarly, the left element of each of the C switches isconnected to the C bus as at 32a, the D switches to the D bus as at 32b,etc.

The invention contemplates a grouping of terminal pins for convenienceof assembly. In the illustrated embodiment, the terminal pins 46 aremolded in a line in five blocks, four blocks 48 carrying 15 terminalpins and one block 50 carrying four pins. The pins 46 extend through theblock a short distance above 52 for soldered connection to the circuitboard and a greater distance below 54 for plug-in circuit connection.The blocks are placed against the bus side of the circuit board with theshort ends 52 of the pins extending up through the pin receptacles 36slightly above the switch side where they are soldered to the conductivesurrounds.

The particular grouping of the pins on the blocks and on the board ishighly specific to a particular engineered embodiment. Needless to say,the division of pins between blocks and the number of-blocks is whollyarbitrary and can vary widely. In the specific embodiment, however, theright hand pin of the block 50 of four is connected to the C switchterminal, the other pins being engaged in dummy receptacles 58 wherethey play a purely supportive function. The remaining 60 bus and switchterminal receptacles are divided among the blocks 48 of 15 pins. Theright hand switch elements 34 of the groups of fifteen progressivelyconverge toward their center at their ends as at 60 to enable aseparation 62 between the pin mounting blocks 48 and 50 for keyboardmounting purposes as will be later described.

The spacer 14 is a rectangular strip of paper board or the equivalent,.008 inches thick having a window 64 therein proportioned to expose allthe switches 28. The

of transversely extending width of the spacer is such that it alignswith the edge of the board remote from the pins 46 and falls just shortof the pins on its other edge. The length is such as to expose only theswitches. Thus, with the left hand end of the spacer 14 aligned with theleft hand end of the board 12, the right hand end of the spacer oveliesthe area of the buses 40. The spacer 14 has a pressure sensitiveadhesive on each side thereof to stick the spacer to the circuit board12 and the contact strip 16 to the other side of the spacer.

The contact stip 16 is a sheet of Mylar having a series rectangularconductive contacts 68 plated on the bottom surface thereof. Thecontacts are arranged such that each overlies one of the switches 28.The contact strip is, of course, mounted to the assembly with thecontact strips down so as to confront the switches 28.

The circuit board 112, spacer 14 and the contact strip 16 have indexholes 70 formed therein such that the three components may be assembledon appropriately located pins to establish an exact relation between theparts.

A pressure pad 18 conforming essentially to the window 64 of the spacer14 is placed on top of the contact strip 16 and in registry with thewindow 64. The pressure pad is a flexible vinyl from l/16th of an inchthick any may have a pressure sensitive adhesive on its bottom surfacefor adherence to the Mylar contact stip.

The cover 20 is a strip of Teflon, 3 /2 mils. thick and dimensioned likethe circuit board 12. The Teflon has a pressure sensitive adhesive onone side thereof by means of which it is secured to the pressure pad,the exposed areas of the contact strip 16, and the exposed areas of thecircuit board 12. Teflon is the material of choice in this applicationby virtue of the ease with which a finger may slide over it. In acharacteristic application of this keyboard, the busses will be cachconnected to like busses serially connected to the key switches of theleft hand or lower keyboard of an electronic organ such that depressingany C key, for instance, of the lower keyboard has the effect ofenergizing or grounding the C bus 40 of the arpeggio keyboard. Thus, thebus side of each of the arpeggio C switches 28 is energized. The notesides 34 of each of the switches 28 are connected individually to keyerscontrolling the output of individual tone generators to the outputsystem of the organ. Thus, as a finger is run along the Teflon cover 20,all of the switches 28 will be closed by the progressive depression ofthe contacts of the contact strip in to bridging relation with the twoswitch elements of each of the successive switches. Since, however, onlythe C switches will be energized, only the C keyers will be operated andsuccessive Cs sounded. Likewise, if the chord CEO is played anywhere onthe lower keyboard, the C, E, and G busses will] be energized and all ofthe C, E, and G note switches conditioned for keyer operation.

This functional incorporation of the arpeggio keyboard an electronicorgan and its mode of operation is all fully set forth in the abovementioned US. Pat. No. 3,358,070 to Young, and as the invention hereresides in the keyboard itself and not in its circuitry or mode of notesounding, illustration is believed irrelevant and unnecessary.

The keyboard of the present invention can be mounted in a variety ofways as shown in the above mentioned US. Pat. No. 3,358,070. A specificmeans of mounting has been devised, however, (Fig. 7) which providesgood accessibility of the keyboard to a players hands involved with theprincipal keyboards and lends itself well to the wanted designcharacteristics of the organ. The front strip 74 of the organ is thatvertical panel between the upper, right hand keyboard and the lower,left hand keyboard. In the specific embodiment it is a metal channelwith the base 76 exposed and decoratively finished and the flanges 78thereof inwardly turned. A slot 80 is formed in the base 76 proportionedto accommodate generously the bulge in the Teflon cover 20 occasioned bythe pressure pad 18. Clips 82 having a central portion 84 adapted toembrace the backside and the longitudinal edges of the keyboard engagethe keyboard in the spaces 62 between the pin blocks 48 and 50. The endsof the clips are backwardly bent as at 86 to approach closely andparallel the flanges 78 of the front strip 74 and have struck-out points88 which engage the flanges 78.

From the foregoing description it will be appreciated that a keyboardhas been devised here which offers enormous advantage in terms of costof components and cost of assembly over that shown in the abovementioned patents to Young and Dyle.

Some dimensions are of interest in that the keyboard should be short tominimize the sweep of the finger necessary to operate it and yet itshould be possible to sound a single note without closing adjacentswitches. The spacing of the elements 30 and 34 of each switch 28 is.031 inches and the switch elements are .031 inches wide, so the widthof each switch is .093 inches. The spacing of the switchescenter-to-center is .172 inches. The contact members of the contactstrip are also .093 inches wide, and, of course, equally spaced with theswitches. The circuitry is, conventioanlly, gold on nickel on copper.The overall length of the keyboard proper as represented by the pressurepad 18 is about 9 inches.

The dimensions given herein are, of course, illustrative and notcritical, but in order to obtain a clean arpeggio effect, it isdesirable that one note of the arpeggio release before the next note issounded. Arpeggios and chords conventioanlly used seldom incorporatesemitone intervals. The spacing of the switches, taken together with therecited thicknesses and materials which go to make up the combinedkeyboard sandwich, result in an assembly sufficiently locally responsivesuch that the pressure of a tip ofa finger will make positive closure ofthe switch directly under the fingertip with a slight effort, but at thesame time not close adjacent switches. In other words, the pressure of afinger might close two adjacent switches if it were centered over thespace between, but if it were centered directly over one switch, theadjacent switches would not be closed. It the area of pressure contactwere broadened, of course, as with the ball of the thumb, as many asfive or six adjacent switches would be closed which might be desired insome arpeggio effects.

It must again be emphasized that the above described embodiment of thisinvention is a highly specific commercial model, and many variations maybe readily imagined without departing from the basic concept thereof. Itis, therefore, desired that this invention be regarded as being limitedonly as set forth in the following claims. I

1. A miniature keyboard for an electronic musical instrument comprising:

a circuit board having a plurality of mutually spaced conductivecontract fingers printed on one side thereof, in a single row, saidcontact fingers being grouped in pairs with each of said pairsassociated with one unique note of at least two octaves of musicalnotes;

An electrically insulating spacer sheet disposed on said circuit boardover said contact pairs and defining a single window therein exposing atleast a portion of each finger of each contact pair with no interveningspacer material between respective adjacent contact pairs;

a flexible sheet of electrically insulating material having mutuallyspaced regions of conductive material thereon and being mounted on saidspacer sheet, each of said regions of conductive material beingdimensioned and positioned to overlie a single one of said contact pairsand being normally spaced therefrom by said spacer sheet;

said keyboard being dimensioned such that adjacent contact pairs overthe entire length of the keyboard are rapidly connected and disconnectedin succession by the pressure of a single fingertip moving therealong.

2. Apparatus as claimed in claim 1, wherein said circuit board furthercomprises a plurality of mutually spaced conductive keying signal bussesprinted on the other side of said board with each of said busses beingassociate with a unique note of the musical scale, a first one of saidcontact fingers in each of said pairs being conductively connectedthrough said board to an associated one of said keying signal bussessuch that a keying signal on said bus will be communicated to each of atleast two contact pairs associated with octavely spaced musical tones,and a second one of said contact fingers in each of said pairs beingadapted to be connected to keying circuitry for said associated tone.

1. A miniature keyboard for an electronic musical instrument comprising:a circuit board having a plurality of mutually spaced conductivecontract fingers printed on one side thereof, in a single row, saidcontact fingers being grouped in pairs with each of said pairsassociated with one unique note of at least two octaves of musicalnotes; An electrically insulating spacer sheet disposed on said circuitboard over said contact pairs and defining a single window thereinexposing at least a portion of each finger of each contact pair with nointervening spacer material between respective adjacent contact pairs; aflexible sheet of electrically insulating material having mutuallyspaced regions of conductive material thereon and being mounted on saidspacer sheet, each of said regions of conductive material beingdimensioned and positioned to overlie a single one of said contact pairsand being normally spaced therefrom by said spacer sheet; said keyboardbeing dimensioned sUch that adjacent contact pairs over the entirelength of the keyboard are rapidly connected and disconnected insuccession by the pressure of a single fingertip moving therealong. 2.Apparatus as claimed in claim 1, wherein said circuit board furthercomprises a plurality of mutually spaced conductive keying signal bussesprinted on the other side of said board with each of said busses beingassociate with a unique note of the musical scale, a first one of saidcontact fingers in each of said pairs being conductively connectedthrough said board to an associated one of said keying signal bussessuch that a keying signal on said bus will be communicated to each of atleast two contact pairs associated with octavely spaced musical tones,and a second one of said contact fingers in each of said pairs beingadapted to be connected to keying circuitry for said associated tone.